Using output-range overloads of SysTime.toISO{Ext}String with formatting code

[drug]

07.07.2019 17:49, Joseph Rushton Wakeling пишет:
> it's possible to do something like `writefln!"%s"(now.toISOExtString)` and have it automatically use the output range overload rather than allocating a new string instance.

This is exactly how it is intended to work: https://run.dlang.io/is/ATjAkx